Hexahydroisoquinoline and its derivatives are important synthetic intermediates to many morphinan compounds including buprenorphine, codeine, etorphine, hydrocodone, hydromorphone, morphine, nalbuphine, nalmefene, naloxone, naltrexone, oxycodone, and oxymorphone. Generally, these compounds are analgesics, which are used extensively for pain relief in the field of medicine due to their action as opiate receptor agonists. However, nalmefene, naloxone and naltrexone are opiate receptor antagonists; they are used for reversal of narcotic/respiratory depression due to opiate receptor agonists.
Currently available processes for the preparation of hexahydroisoquinolines tend to be inefficient and low yielding because intermediates are isolated after each reaction step. Given the commercial importance of hexahydroisoquinolines, a need exists for streamlined, efficient processes for their preparation.